FINALLY we can find out how much caffeine is in the coffee WE drink, instead of relying on sketchy google results
TLDR: 18g coffee brewed to same extraction:
1 double espresso = 110 mg
300g cup of pourover = 170 mg
50% more caffeine from the same amount of coffee and same extraction!
Seems like time of extraction has a lot of effect on the caffeine amount. So the speed of an espresso pull means less caffeine is extracted
Also instant coffee has about half the amount as pourover (and that's using a stronger concentration than the instructions say)
He also does light roast vs dark roast, etc